The stapling instrument of the present invention may have many applications where it is desirable to implant and form a staple from one side only of the item being stapled. The stapling instrument is, however, particularly adapted for use as a surgical stapling instrument and will, for purposes of an exemplary showing, be so described. The surgical stapling instrument of the present invention could be constructed so as to be reusable, as will be briefly discussed hereinafter. Nevertheless, it is particularly well adapted to be inexpensively produced as a single-use, disposable instrument, and for that reason it will be so described.
In recent years surgeons have come more and more to the use of surgical staples (sometimes referred to as staple sutures), rather than conventional thread sutures, for the closing of wounds or incisions in the tissue of a patient. This is true in part because the use of surgical staples is a far easier procedure. Of even greater importance, however, is the fact that the use of surgical staples is very much faster, thus reducing the time required for suturing. This, in turn, reduces the length of time a patient must be maintained under anesthesia.
Prior art workers have developed various types of surgical stapling instruments, examples of which are taught in U.S. Pat. Nos. 3,618,842; 3,643,851; 3,717,294; 3,836,555; and 3,873,016. In general, these prior art surgical stapling instruments are complex in construction and expensive to manufacture. They do not lend themselves well to be constructed as disposable instruments. Such prior art surgical stapling instruments generally require a replaceable cartridge for the staples and a portion of the force necessary to actuate these instruments is expended in shifting a staple from a row thereof within the cartridge to a forming means, prior to the formation of the staple.
Prior art workers have also devised numerous types of surgical clip applicators having forcep or tweezer-type clip-bending arms. Examples of such structures are taught in U.S. Pat. Nos. 1,203,269; 2,096,173; 2,256,382; 2,733,441; 2,744,251; 2,789,288; 3,047,874; 3,152,336; and 3,775,826. The last mentioned patent is of interest in that it teaches a disposable wound clip applicator. U.S. Pat. No. 1,203,270 teaches a wound clip forceps having a pliers-like portion with rotatable jaws that bend the wound clips into their clamping configuration.
Surgical clamps differ markedly from surgical staples both in the complexity of their configuration and their mode of forming and implanting. A surgical clamp is of more complex configuration than a surgical staple and is normally bent at its middle portion to clamp it upon the skin of a patient, having small skin engaging tines. A surgical staple, on the other hand, is of much simpler construction and is actually formed so that its legs are implanted in the tissue of a patient.
U.S. Pat. Nos. 4,109,844 and 4,179,057 teach disposable surgical stapling instruments, each provided with an anvil plate terminating in a coextensive anvil surface. Both of these surgical stapling instruments, however, employ a conventional staple former. Such a staple former tends to shear minute particles of the staple during the forming process since, during the staple forming process, the staple is pinched between the former tines and the anvil.
The present invention is directed to a small surgical stapling instrument which may be readily produced as a disposable, single-use instrument. The instrument employs a pair of rotatable formers to cause a surgical staple to be formed without shearing minute particles of the staple during the forming process. The rotatable formers cause portions of the staple to be implanted into the tissue of a patient. The instrument is extremely simple in construction and inexpensive to manufacture. The instrument may have an anvil plate with a coextensive anvil surface so that none of the force required to actuate the pair of rotatable formers is utilized to advance a surgical staple to a proper position for forming. The rotatable formers provide support for the staple as it is formed and placed into the tissue of a patient, thereby permitting the use of finer wire staples than heretofore possible. This, in turn, produces a better cosmetic result.